control_keys
The program can be stopped by typing control-Q.
An interrupt mechanism that will stop the current computation but
not the program has not yet been implemented for Apollo.
Control-Z is interpreted as an EOF by the Fortran run time I/O
library. Program execution is terminated after this control.
The program can be stopped by typing control-Y.
Control-C on a Vax will terminate execution of the command that is
being executed and then return control to the command reading routine.
The graphics buffers are emptied if plotting is in progress, to make
sure GKS is in a well defined state. The terminal printing buffer is
flushed. Other I/O channels are left untouched, hence a dataset
attached to logical unit 12 (used for short term sequential dataset
access) may be left open. This is harmless since the dataset will be
closed when a new dataset has to be opened. The same goes for dataset
access that is transparent to the user.
The RTL I/O routines have to be replaced so as to avoid blocking of
the terminal I/O channel when the AST occurs in an RTL routine. The
reason for this is that AST intercepting routine simply unwinds the
stack until the routine which has been LIB$ESTABLISH'ed, usually
the command reading routine.
Control-Z is interpreted as an EOF by the Fortran run time I/O
library. Program execution is terminated after this control.
CMS lacks control keys.
The program can be stopped if necessary by hitting the CP key and
then typing IPL CMS. There is no elegant interrupt when a plot is
being produced in interactive mode.
The standard EOF mark in VM (a blank return) is intercepted and
is treated like a blank input line.
The line separation character (#) is switched off during startup
of the program since the symbol has a meaning in Garfield.
Keyword index.
Formatted on 10/11/98.